cryogenic manifolds

Cryogenic Liquid Manifolds

Applications Guide

Mark Allen

Continuing Education Publication

TM

Cryogenic Liquid Manifolds Applications Guide3

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Cryogenic Liquid Manifolds Applications Guide3

Notes on Using this Book:

This book is presented as a service to users of cryogenic gas liquid manifolds to assist in understanding these deceptively simple devices.

Second Edition 16 February 2005. Replaces an earlier edition dated 5 January 2005.

Notes

This book in both print and electronic versions is Copyright 2005 BeaconMedaes and Mark Allen. All Rights are Reserved, and no reproduction may be made of the whole or any part without permission in writing. Distribution of the Electronic version is permitted only where the whole is transmitted without alteration, including this notice.

Comments on this book or on any aspect of medical gases are welcome and encouraged. Please send to [email protected]

4Cryogenic Liquid Manifolds Applications Guide Cryogenic Liquid Manifolds Applications Guide5

Contents

Table of Contents

Introduction 5Some terms used in this booklet.

Liquid, glorious liquid 5What makes liquid a good choice for many facilities?

What is cryogenic liquid 5The basics of cryogenic liquid gases. What they are and how they act. Cylinders versus Containers 7How cryogenic liquids are stored and how their containers behave.

The unexpected 8Why liquid manifolds sometimes dont seem to work as expected.

When is a liquid manifold not a good idea 17The limits to liquid manifolds.

Other Options 13The limits to liquid manifolds.

Annex A 20Container DataRepresentative data on containers and cylinders.

Annex B 20Safe work practicesWorking with cryogenic containers and cryo-gens require some special practices.

Annex C 20Alarms and Alarm ResponseWith a liquid manifold comes some extra alarms and some extra actions when they ring.

Annex D 20A Typical Liquid Manifold RoomAn example layout of a typical manifold room.

Annex E 22DimensionsThe dimensions necessary to lay out a manifold.

Annex F 25SignageThese are the signs required to be posted on the door of a manifold room.

Annex G 29Using Bulk and MiniBulk Sources with the Lifeline ManifoldImplementation of the Lifeline manifold as a bulk station control is very feasible. Here are some guidelines to be observed.

Annex H 31Manifolds located outdoorsThis is the NFPA 50 Table referenced in NFPA 99.

Annex I 32Sizing a ManifoldData here will allow the selection of a manifold based on type and size.


Introduction

Introduction

This booklet is intended to help the user or specifier of a liquid manifold and to a lesser extent a bulk gas system understand how that system works and what are some of the pitfalls of using one.

In this booklet we will use NFPA parlance for Cylinders (meaning high pressure cylinders containing gas) and Containers (meaning a cryogenic liquid container containing liquefied gas at supercold temperatures). We will also speak of the Primary header as the one in service, the Secondary header as the one on standby, and the Reserve Header as the one which will serve the system only if both the primary and secondary run empty. Liquid, glorious liquid

Medical facilities are always searching for ways to save money. One of those golden opportunities may be found by installing or converting to liquid manifolds for some of the gas delivery systems.

Liquid manifolds are very attractive for two simple reasons: Liquid is much less expensive to purchase than gas in cylinders (in most localities) when calculated on a volume of gas basis. The potential savings can be considerable. Although portable liquid containers are individually heavy, each one may contain as much gas as 17-25 cylinders. The labor involved with changing a couple of liquid containers is nothing when contrasted with changing that many cylinders.

To give an example, one facility reported their costs for a cylinder of nitrogen to be $6.50. They paid $2.30 per month for demurrage (rental) on a cylinder. A container of liquid nitrogen cost them $51.05, and demurrage was $25.00 per month. Although the liquid container is clearly more expensive, it contained 21.5 times as much gas equivalent as the gas cylinder. The liquid container must also be changed less often, saving labor. The facility used a $10.00/hour labor rate. So for this facility, a cubic foot of gas delivered from cylinders cost approximately 2.8 cents. A cubic foot of gas delivered by liquid costs 1 cent. Thats a big savings.

At this rate, the facility estimated a cost of $4,312 for this gas per year for the manifold. With a liquid system, they could cut this to $2,018, saving 53% or $2,294. Replacing the manifold cost about $6,000, so it was easily within the 3 year payback required.

Liquid is an option for oxygen, nitrogen, nitrous oxide, carbon dioxide, and argon systems. Taken together, the total savings can be very interesting indeed.

Many facilities realize these savings and operate their liquid manifolds with little trouble, but others find them frustrating to operate and the cost savings elusive or invisible. The facility who actually loses money on a liquid conversion is not unheard of either. What is the secret?

Cryogenic liquid containers, unlike cylinders, take more management than simply changing the empties. Under the best of circumstances (when the container is clean and new) they will perform pretty close to their specified limits, but even then they do have limits. When one is used to dealing with cylinders, which are quite straightforward, containers can come as a surprise. They can seem cranky, uneven, and wasteful. When a container is old and has suffered the travails of transportation, being dropped off trucks and handcarts, and being generally maltreated, these symptoms can be greatly exaggerated.

Facilities who succeed with liquid systems understand how the containers work and that they need to be managed to be at their best. They are however reasonably intuitive if you understand how cryogenic liquids behave.

What is cryogenic liquid

In accordance with the laws of materials, almost every material will vaporize into a gas above some temperature, and cooled below that temperature will be a liquid. Medical gases are simply in the vapor state at standard room temperatures but behave in every respect in accordance with these rules.

So, if for instance we cool standard air, we should be able to change it from a gas to a liquid. And so we can - but we have to cool it quite a lot - to minus 194 degrees C (minus 318 degrees F). Because the product is at such extremely low temperatures, it is referred to as a cryogenic liquid.

Cooling air to minus 194 degrees C offers a challenge and an opportunity. Oxygen (which is about 21% of standard air) liquefies at minus 182 degrees C, and nitrogen (78% of standard air) liquefies at minus 196 degrees C.

Keeping air mixed as a liquid is a problem if you want liquid air but an opportunity if you only want liquid oxygen or liquid nitrogen. Careful control of the temperature allows air to be separated into its constituent gases. This is how almost all oxygen or nitrogen used in a medical facility is produced.

Cylinder gas is typically the liquefied gas allowed to warm back into vapor state and packaged in cylinders.

A cubic meter of oxygen gas (equivalent to 1,000 liters


Cylinders vs. Containers

or 35.3 cubic feet) at 70F and 1 atmosphere pressure (standard temperature and pressure) will occupy a cube 1 meter (3 feet) on each side. Pressurized in a cylinder to 2,200 psig, the same gas will occupy 6.6 liters or a space 188 millimeters on each side. Cooled to liquid state, the same amount of gas will occupy 1.16 liters, or a cube 105 millimeters on a side. This difference means that for the same size of container we can store 1.8 times as much gas.

However, since cryogenic liquids can be stored at low pressures, the containers do not need to be as strong, and thus can be made in much larger capacities. One example of a small liquid container will hold about 114,000 liters of gas equivalent, and large ones can run into millions of liters. By comparison, a typical cylinder used on a medical system is capable of storing about 6,700 liters of usable gas. Holding more, the containers need to be changed less often, resulting in labor savings.

Containers holding cryogenic liquids are thus a superb way to store gases in volume. However, there are limits on the effective use of containers, which we will discuss below.

Cylinders versus Containers

While safely storing gas in cylinders at 2,200 psig (and sometimes higher pressures) is not a trivial matter, safely storing and transporting a cryogenic liquid at these incredibly low temperatures is even more challenging. Cryogenic containers are specifically designed for two functions: To safely insulate the cryogenic liquid and ensure the

user is largely protected from the extreme cold. This allows the liquid to be transported and stored.

To allow the user to withdraw the liquid either as liquid or as gas for use.

To explain the basics of how these containers operate, we can look at a typical portable container as might be used with a Lifeline liquid manifold. This example

Guage

Relief Valveand Burst Disc

Fill Line &Liquid Tap

Vent

Gas Tap

Contents indicatorPressure Builder ValvePressure Building Regulator

OuterVessel

Figure 1A Representative Portable Liquid Container

(Note: Containers vary in detail)



stands about 160 cm (62 inches) tall and is about 50 cm (20 inches) in diameter. It contains some 180 liters of cryogenic liquid when full. Although we have chosen to illustrate this particular container, all cryogenic containers are similar and all have the basic items described here, although details of construction vary greatly. (Please refer to Figure 1 and 2)

A tour through a cryogenic container must begin with the vessel which will actually hold the liquid. Typically made of stainless steel, this inner vessel is placed inside of another vessel. The outer vessel is what youre looking at when you see a cryogenic container.

If a cryogenic liquid is exposed to temperatures higher than the boiling point of the cryogenic liquid, it will very rapidly and possibly explosively convert into gas. Preventing heat leakage is critical to the effective use of any container. To minimize heat leakage, between the inner and outer vessels there is usually some form of insulation. Equally or more important the space between the two is evacuated to a very deep vacuum. Given the extreme temperature

difference between the inner and outer vessels, every molecule left in the space will transmit heat and increase the heat leak rate. The absence of anything which can conduct heat between the vessels is essential in building a functional cryogenic container.

Now with the two vessels in place and insulated, the first concern is to get the liquid into the inner vessel. For this, a Fill connection is typically run to the bottom of the inner container. This line can then be used both as a fill line and a liquid withdrawal line.

To fill the container, you must resolve the basic physics which say you cant put something in without taking something out. (In the case of a liquid container, this is something of an oversimplification, since it is actually possible to fill the container by manipulation of the interior temperature, actually using the cryogenic liquid to condense the gas internally and reduce the internal pressure by that means. This manipulation is an important step in filling large containers and is a one of the few differences between small and large

Gas Tap

OuterVessel

Figure 2Inside a Representative Portable Liquid Container

(Note: Containers vary in detail)

InnerVessel

Internal Vaporizer

Pressure Builder

Pressure BuilderDischarge

Fill and Liquid Line

Vent Line

Note that the container is shown full of liquid in this illustration, however the color is not accurate.


of regulator which maintains the pressure of the headspace (the space between the top of the vessel and the liquid).

It is very typical for the pressure builder, the internal vaporizer and the gas connection to be interconnected. This allows excess pressure in the headspace to be drawn off and used, which is particularly important when usage is low. The circuit functions so that if the headspace pressure rises, any gas drawn from the container comes first from the headspace. Once demand exceeds the NER for the container and the headspace pressure falls, the pressure builder will attempt to satisfy the demand. If the demand exceeds the output of the pressure builder (which has quite limited vaporization capacity), liquid will be drawn into the internal vaporizer and converted to gas there.

On any liquid container one can find these same basic elements, albeit with variations suited to the capacity of the system. For example, on portable containers, the pressure builders vaporizer is mostly internal, on a bulk station it is usually external and can often be seen on the bottom of the vessel. Large vessels usually have a clearly labelled Top Fill and Bottom Fill connection, whereas portable cylinders typically have only a liquid connection and a vent. Large tanks also have a trycock to determine how full they are, whereas portable containers have only the vent line and are often filled by weight.

containers. Large containers will have separate top fill and bottom fill connections to facilitate this.) A method for allowing something out is provided in the form of a vent connection. To fill the container, open the vent and pump in the liquid, then close the vent. Simply by making the vent tube a specific length, one can also prevent overfilling the container.

Once liquid is in the inner vessel, the question of heat leakage arises. Since no insulation can be perfect, even a closed container will gradually boil off liquid to gas. The rate at which this happens is called the Normal Evaporation Rate (NER) for the container. Over time, the NER will cause the internal pressure to increase. Eventually, this gas must vent or the container will explode. Two devices are installed to handle this: a safety relief valve and a burst disc. The relief valve will open and close at its set pressure to vent off excess gas. Should the relief valve fail or not be able to handle the volume (as sometimes happens if the insulating vacuum is lost), the burst disc will blow out and vent the pressure.

Now with liquid inside the container, there needs to be a way to draw gas off for use. This could of course be accomplished by drawing liquid through the fill line as mentioned earlier. However, since what comes out of the liquid tap is a very dangerous liquid, it needs to be converted to a gas before its usable.

External vaporizers are typically used with larger containers and installations demanding large outputs (bulk gas installations are of this type). External vaporizers can also be used with portable containers under some circumstances.

However, smaller containers also have a vaporizer inside the container. This allows a gas connection to be provided on the container. This internal vaporizer is essentially a tube tacked to the inside of the external vessel. It pulls heat from the outer skin of the container and uses that heat to convert the liquid to gas.

There is one further basic physics challenge to using liquid containers, and that is that you cannot draw liquid out of a closed container without replacing it with something. One could of course open the vent line, but that would admit air and contaminate the gas inside the container. Clearly that would be inappropriate, so instead we rely on the fact that a little liquid makes a lot of gas. Some liquid is drawn from the bottom of the inner vessel, allowed to pass through a small version of the internal vaporizer and thus change to gas and expand. That gas is then returned to the top of the inner vessel (the headspace) where it provides the necessary volume and pressure to push out more liquid. The amount of gas made by this pressure building circuit is determined by a special kind


About the Normal Evaporation Rate (NER)

The NER for liquid containers will vary a great deal. In all the examples we have used an NER of 1.5% for new and clean containers, but in fact this rate is not fixed and is often very much higher. NER for a given container will vary depending on several factors includ-ing the temperature of the liquid (nitrogen (-196C) has a higher NER in the same container than oxygen (-183C)), ambient temperature, condition of the con-tainer, exterior heat sources (for instance bulk tanks are usually painted white to reduce solar heating), whether the pressure builder is open or closed, etc. Portable containers are subject to all sorts of abuse which tends to increase their NER. If the container is dirty, dented or otherwise in less than prime condition, it is common to have a higher NER. As containers age, the vacuum between the inner and outer vessels also tends to degrade and the NER will rise. BeaconMeds recommends that NER as low as 1.5% should be reliably expected only in fixed containers and that an NER of 3-5% be used when making calculations with portable containers.


The Unexpected

The unexpected

Failures in systems sourced from liquid manifolds are not typically a failure of the manifold itself. This will be especially true with the Lifeline manifold which has an enviable history of reliability. More typically, liquid manifolds prove unsatisfactory because their operators simply do not understand their limitations and apply them incorrectly.

Some typical scenarios:A facility sees the opportunity to realize the huge cost savings liquid can offer. They attempt to convert an existing gas manifold simply by attaching liquid containers. They find: The manifold crashes, sometimes immediately,

sometimes later, because the pressure relationships in the manifold are set for high input pressures which liquid containers do not always deliver.

The manifold crashes because of cryogenic temperatures on regulators not suited to the conditions.

The system crashes because of inadequate flows (portable liquid containers by themselves cannot typically output gas at cylinder rates).

They get no source alarms, but the area alarms go off because the manifold cannot maintain pressure.

A facility installs a proper liquid manifold but still suffers frustration with their system. These frustrations might include: The disturbing experience of walking into the manifold

room and finding the containers all hissing away like theyve suddenly sprung leaks.

Attaching a completely unused container to the manifold and finding its actually empty. Then trying another container only to find that theyre all empty!

Checking the manifold header pressure gauges faithfully once a shift and still having the secondary in use and reserve in use alarms go off moments later - but all the gauges read just what they always do!

Supplying the manifold with four full containers. Left header in service, right header on standby. The manifold never gives an alarm for Changeover until both the Changeover and Reserve in Use alarms go off simultaneously. Upon investigation, both headers are empty.

Having the system crash because the new liquid manifold cant deliver a flow rate the old cylinder manifold never had a problem with.

A daily examination of the manifold reveals the Secondary header is drawing down at a faster rate than the Primary.

Having an employee die from asphyxiation in the container storage room because he didnt know the venting nitrogen had displaced all the air in that closed room.

All of these are phenomena which can be traced to normal liquid containers. As they will suggest, these can result in very serious problems. But to balance the account, many facilities find these systems entirely satisfactory and never experience these problems or succeed in preventing them from becoming serious by good management.

As mentioned before, liquid containers all have a natural rate of heat leakage called the Normal Evaporation Rate. A clean, new container filled with oxygen will have a typical NER in the range of 1.5% per day (but see sidebar About the NER). To see what this means, consider a container filled with 165 liters of liquid oxygen. This would vaporize into about 120,000 liters of gas. If we never touch this container, the pressure will gradually build up until the safety valve begins to bleed off the excess pressure (the exact pressure at which this will occur will vary with the container rating). If we listen, well hear this as the steady hiss of escaping gas. It is not a leak, but a normal phenomena. Each day, the container will vent off about 1.5% of its contents when full. That is, 1.5% of 120,000 liters or 1,800 liters. This will not decline as the container empties, but will continue essentially at this rate, day and night. If we leave this container alone for 30 days, it will be half full. If we leave it for 60, it will essentially be empty. The same container filled with Nitrogen has an NER of 2%, so it will last only 50 days. Note that we have not used any gas - this is simply loss due to the NER of the container.

Attach the container to a manifold with three more containers identical to the first. We then have the configuration shown in Figure 3. If we use no gas whatever, the NER of these four containers filled with oxygen will require they vent 7,200 liters of gas per day (1,800 x 4).

If the facility in our example uses 3,600 liters per day, the containers will only have to vent the other 3,600 - but they will vent as much as needed to absorb the NER.

There are other situations to consider as well. For instance, whatever amount the facility uses during the day, if they use none at night the containers will probably

Figure 3A Basic Liquid x Liquid Manifold

Primary/Secondary

Primary/Secondary


The Unexpected

be venting every morning. Although their usage may be mathematically adequate, it is not steady, whereas the heat leakage is essentially constant. To totally avoid loss of the gas, the draw from the containers must match or exceed the NER not as an average but on a nearly continuous basis.

This seems to present a problem, as no medical facility ever has entirely smooth demand. However, there is a degree of flexibility designed into the containers. A typical container has a pressure builder pressure 50-100 psi lower than the relief valve setting. Under demand, the container will drop to the pressure builder pressure and hold at that pressure until empty. If the demand stops, the pressure will build toward the relief valve pressure at a rate determined by the NER and how full the container is. Full containers will reach the pop off pressure faster than nearly empty containers simply because they have less headspace to pressurize.

On a gas manifold, any gas drawn will come from the primary header until it is empty, at which time the manifold switches, an alarm is initiated and the manifold draws from the secondary header. However a liquid manifold includes a code mandated feature called an economizer to reduce waste. The manifold first draws off the container which has the highest pressure, and that will include the containers on the secondary header. The manifold is designed to draw from the primary header only after the gas in excess of the NER is drawn away from both the primary and the secondary headers. In using 3,600 liters/day, each of the four containers would contribute about 900 liters to the demand and would vent about 900 liters2.

So long as the demand remains below the NER of 7,200 liters per day, the surprise is that all four containers will empty at essentially the same rate. If your system were configured like Figure 3, the first indication you would get that the gas was running out would be the Changeover alarm, followed immediately (seconds later) by the system running empty.

Once the demand rises over the NER for the containers, in our example 7,200 liters per day, the manifold will begin to draw any additional gas preferentially from the primary side3. As an example, if demand were at 8,000 liters per

day, the secondary header would contribute 3,600 liters and the primary header 4,400 liters. The manifold would also then operate as we would expect: Primary runs empty, Secondary takes over, Alarm indicates Changeover. As you can see from the above, a liquid manifold cannot be operated safely without safeguards additional to those required for gas cylinders. One safeguard NFPA mandates is the provision of a third header containing gas cylinders enough for 24 hour supply and called the Reserve. Adding the reserve, we have the configuration illustrated in Figure 4. This manifold is designed to cascade in this specific order: Primary header in service, no alarms - Primary runs empty, Secondary begins to serve, Changeover alarm - Secondary

runs empty, Reserve begins to serve, Reserve in Use alarm - Reserve begins to run low, Reserve low alarm - Reserve runs empty, low pressure alarm(s).

A properly configured liquid manifold with Reserve will operate more safely than the system shown in Figure 3, but still may confuse the operator. The operator may expect the standard sequence but instead find the Changeover alarm and the Reserve in Use alarm ring out virtually simultaneously. This kind of event will occur if the demand is less than or equal to the NER.

Even when demand is greater than the NER, the operator must remember that when the Changeover alarm rings, the Secondary is not full, and the time between the Changeover alarm and the Reserve in Use alarm may be quite a bit shorter than the time from full to Changeover. It is entirely possible the operator will go to the manifold

Figure 4A NFPA compliant Liquid x Liquid x Gas Manifold

Primary/Secondary

Primary/Secondary

Reserve

2 This is an ideal picture. In practice, containers are never perfectly balanced and the ratio of useage to vent could vary greatly between the four containers. However, it may be relied upon that at least 7,200 liters would go somewhere.

3 There is a way in which even this may not be true. Liquid containers come in at least two pressure settings. If the containers on the secondary are of a higher pressure type than those on the primary (or are seriously misadjusted), it is entirely possible to have the secondary header drain down faster than the primary despite the manifold settings.


but they are also subject to being overdrawn. Overdrawing a liquid container can occur suddenly and be obvious, but equally the problem can sneak up on you.

Overdraw manifests itself when the demand on the container is more than the pressure builder can compensate for. If the pressure builder cannot keep the headspace pressure up, the internal pressure falls so low that liquid cannot be pushed out. The surest way to make this happen is to close the pressure builder or, since containers normally arrive on site with the pressure builder closed, never open it in the first place.

Failure can also occur even though the container is not being overdrawn, but is actually operating within specification. When the pressure builder and internal vaporizer of a container are in continuous use, they will chill the outer vessel of the container and in certain environmental conditions ice will form on the outside of the container. This ice normally appears first at the bottom of the container and is not an unusual thing to see. With prolonged use, the ice can climb up the sides of the container and begin to act as an insulator, preventing heat from getting to the vaporizer. When this happens, either the pressure builder will fail to make enough pressure or the vaporizer will begin to pass liquid. If the pressure builder fails, the situation is the same as when the pressure builder is closed. However, the recovery time can be much longer as the ice must be melted away to restore proper function.

When an internal vaporizer is overdrawn and liquid begins to pass into the manifold the results can be much more dire. Manifolds are commonly not designed to take in cryogenic liquid, and the damage to the primary regulators can be serious. The pressure may no longer be controlled and the system may lose pressure or relief valves may activate, aggravating the original problem. Replacement of the regulators may be required to restore the manifold to full service.

In cases where overdraw is possible or probable, it is best not to rely on the internal vaporizer but to install an external vaporizer of larger capacity.

Another phenomena associated with liquid containers is variation in output between the containers themselves. It is not uncommon to have two seemingly identical containers on the same header which have slightly different internal pressure settings. In such a case, the container with the higher internal setting will feed the system in preference to the container with the lower setting. A characteristic finding is one container on a header far more full than the other. This is usually more annoying than serious, but in extreme cases, lower system capacity may result.

The Unexpected

expecting to change the Primary containers but find the Secondary containers also in need of replacement.

Quality manifolds like the Lifeline Manifold are fully automatic and will automatically exchange Primary for Secondary. This is an important feature which prevents the manifold from swinging back to the original Primary header as soon as the empty containers are changed. By rotating the Primary role between the two liquid headers, the containers are more completely drained and can be changed in sequence. Some manifolds are only semi-automatic and do not perform this exchange without a manual operation. Semi-automatic manifolds, if not operated correctly, will inevitably fall to the Reserve on a periodic basis. This complicates the operation of the manifold and increases the risk of the system running empty.

So far, we have discussed only manifolds which are two containers to a side. There are two other variants which should also be discussed.

First is a manifold with only one liquid container on each of the Primary and Secondary headers. These may not be used under the NFPA 99 2002 version, but would be permitted under NFPA 99 2005. Arguably, they were also permitted under earlier versions. Naturally they contain less gas, but have the corresponding benefit of a lower NER.

Second is a manifold version with one or two liquid containers as Primary with a Secondary composed of gas cylinders. A Reserve header of cylinders is mandated for this configuration as well.

This Liquid x Gas x Gas configuration has the advantage of lowering the NER as low as that of one container. It has the unusual characteristic that the liquid header is always the Primary header. When the Primary runs empty, a Secondary in Use Alarm will be activated, and the Secondary will serve the demand. However, when the Liquid container(s) is(are) replaced, the liquid header will immediately revert to being Primary. These manifolds never allow the Secondary to become Primary and are therefore an exception to the general rule on how manifolds should rotate the stock.

Liquid x gas x gas manifolds require the operator to replace the secondary cylinders based on a predetermined threshold, and these cylinders will therefore usually be sent back partially full. This waste must be accounted for when calculating the potential savings from such a system.

Liquid containers are not only subject to being under utilized and venting off their contents because of the NER,


With liquid containers it is important to know the peak demand likely to be experienced. The manifold will be limited to the vaporization capacity of the containers. If the internal vaporizers cannot serve the peak demand, an external vaporizer might be a solution. If the containers themselves are inadequate, a mini bulk or bulk tank may raise output high enough. At approximately 2,200 ft3/hr (62,260 liters per hour) in demand, the limitation may become the manifold itself, at which point a Lifeline manifold should not be used and a bulk station with appropriate equipment should be considered.

It is entirely possible to have a facility whose lowest use will be below the NER for a single container but whose peak use will be above the capacity of those same container(s). A facility in this situation must decide if it can live with the waste inherent in two containers in order to increase the peak output, or if a liquid manifold is the right choice at all.

It is always best where possible to place liquid manifolds out of doors (see Annex H). Manifold rooms and any storage enclosures indoors must be vented adequately. NFPA 99 mandates mechanical ventilation for these rooms or enclosures. If the manifold room cannot be adequately ventilated, liquid should never be considered.

Environmental factors which will increase the NER must be considered and dealt with. A typical example is placing the containers outdoors in the hot sunshine. The heat and solar radiation will drive up the NER. (Placing containers outside in cold climates can have the opposite effect - reducing the maximum output of the container.)

Other OptionsWhen a liquid manifold does not seem a good option, what other options can be considered?

There are several, depending on the circumstances which makes the liquid manifold undesirable.

If the problem is that the usage is likely to fall below the NER from portable liquid containers, clearly it is always an option to return to gas in cylinders. There is no floor on the output of a cylinder manifold, but naturally there is a ceiling. The ceiling is essentially set by how often one is willing to change the cylinders. A well sized manifold should not need attention more often than once a week, but clearly there is no technical problem with changing the cylinders more frequently if necessary.

The limitation may be high variation in usage. In such cases, the system will fall below the NER at times and at other times will challenge the containers output. A typical case where this may prove a problem is a nitrogen system used for tools. In some cases, it helps to simply

When is Liquid not a Good Idea

Some users interconnect the vent lines of their containers to equalize the internal pressures and thus force the containers to feed equally. This practice can work, but can also have serious consequences for operator safety and should only be undertaken by someone very knowledgeable about safe practices with containers.

When is a liquid manifold not a good idea?

Liquid manifolds can be extremely cost effective, and the savings from using liquid both in dollars and labor can be sweet. The facilities which realize these benefits without the attendant frustrations have one common characteristic: their liquid manifolds are properly applied.

There are many, many situations where liquid manifolds can work well and the user can benefit. However, the closer one gets to the edges, the more likely there will be issues. For example, there are several makers of liquid containers, and a given gas supplier may use containers from any number of manufacturers, in any number of different sizes, pressure ratings, and conditions. Containers which are visually identical will still have individual characteristics. What worked on paper with a new and up-to-spec container may not work so well with an old, used container from another manufacturer. Therefore, it is best to play it safe, leaving some margin of error to encompass the variations in the containers and the experience of the operators.

With liquid containers there is a floor under which they should not be used. In simple terms, this floor is the NER, and a facility which does not use each day at least the NER for the number of containers installed should be considered unsuitable for liquid. Facilities which on an average day use the NER or more should remember to consider both the non-average day and the night. A facility which is close to the NER with average usage will probably find they are below the NER when usage is low. For example, a Surgery center who operates eight to twelve hours a day must be prepared to vent off (i.e. waste) gas for part of the time. It may seem surprising, but liquid may actually be so much cheaper than cylinder gas that they can do this and still save money. However, it is also possible that this waste will also evaporate any savings they might have otherwise enjoyed.

Remember that the NER will vary with the number of containers. The lowest NER will come with a one container liquid x gas x gas manifold. A liquid x liquid x gas manifold with two containers will have twice that NER, and a liquid x liquid x gas manifold with four containers will have four times the NER. BeaconMeds never recommends more than 2 containers per header. (see Other Options below for alternative systems configurations).


Other Options

use a better container. Since permanent tanks are not subject to the abuse inherent in transporting portable containers, the NER can be held lower and is more reliable. A minibulk for instance may have an NER of 0.6% as opposed to 1.5% with a portable. This lower NER can help solve the problem, but be aware that these are usually much larger vessels as well, and must be filled from a truck directly, requiring the cooperation of your gas supplier. They also require an external vaporizer. In these cases, consultation with the container supplier and the facilitys gas supplier is essential.

The Lifeline manifold can make an excellent control for these systems, but they can also overpower the manifold. The limitations on the use of a manifold as a control device in these circumstances should be thoroughly understood prior to installation.


Annex A

Examples of containers and cylinders.

Type H

C

ylinder

Small LP

Liquid Portable

Small H

P Liquid

Portable

Large LP Liquid

Portable

Large HP

Liquid Portable

Sample

Minibulk Tank

Sample B

ulk Tank

Model

Chart 160 M

PC

hart 160 HP

Chart 265 M

PC

hart 265 HP

Taylor-Wharton

EF 450 HP

Taylor-W

harton 6000

Norm

al Max. Pressure

2,200 psi15.2 m

Pa230 psi1.6 m

Pa350 psi2.4 m

Pa230 psi1.6 m

Pa350 psi2.4 m

Pa350 psi2.4 m

Pa250 psi1.7 m

Pa

Diam

eter in/cm9/22.8

20/50.820/50.8

26/6626/66

30/76.296/240

Height in/cm

51/13059.6/151

59.6/151 57.8/132

57.8/132 74/188

312/800

Weight (full)lbs/kg

O2

153/69.5629/285

640/290935/424

924/4201,637/736

83.9k/38.0k

N2

517/234531/241

758/344754/343

1,364/61367.7k/30.7k

CO

2667/315

967/439

N2 O

640/3031,008/456

Argon

710/322717/325

1,062/4811,046/475

1,832/82496.3k/43.6k

Contents (G

as at STP)

ft 3/liters

O2

244/6,9004,577/129.5k

4,348/123k7,183/203.2k

6,811/192.7k11,000/311.3k

676k/19,167k

N2

226/6,4003,685/104.2k

3,464/98k5,769/163.2k

5,438/153.8k8,750/247k

547k/15,494k

CO

2434/12,300

3,382/95.75,305/150.1

N2 O

558/15,8003,207/90.7

5,034/142.4

Argon

4,448/125.84,226/119.5

6,982/197.56,634/187.7

10,700/302.8661k/18,720k

NER

(%/day)

O2/ N

2/ N2 O

NA

1.4/2/NA

1.4/2/0.51.4/2/N

A1.4/2/0.5

O2 =

1O

2 = 0.25

O2 W

ithdrawal R

ate ft 3/hr / liters/hr

Unlim

ited350/9,905

350/9,905400/11,320

400/11,320575/16,272

Unlim

ited

N2 O

/CO

2 Withdraw

al R

ate ft 3/hr / liters/hrV

ery High

110/3,113110/3,113

NS

NA

= N

ot Applicable. U

sually, these containers are not used with this gas.

NS =

non-standard. It may be possible to use a container in this m

anner, but the supplier should be consulted.U

nlimited indicates that although there obviously is a lim

it, it is so high as to be effectively irrelevant with m

edical gases.V

ery High indicates the lim

it is so high that only rare situations will approach it.

Container and Cylinder Data


Annex BSafe work practicesCryogenic liquids such as liquid oxygen, nitrogen and argon are liquefied gases that are kept at very low temperatures. Contact with these liquids can result in burns, eye irritation and allergic reactions.

Ventilation system

The amount and type of ventilation needed depends on the size and layout of the room. However, continuous mechanical ventilation is required wherever cryogenic containers are stored indoors.

Make sure ventilation systems are designed and built so they do not result in an unintended hazard.

Ensure hoods, ducts, air cleaners and fans are made from materials compatible with the gas used, and are regularly maintained and cleaned.

Employee training

All employees who handle cryogenic liquids should receive appropriate training. Only trained employees should be permitted to handle or work with cryogenic containers. Training must include at least:

Properties of the cryogen both as a liquid and a gas. Specific instructions on the equipment being used,

including safety devices. Approved materials that are compatible with the

cryogen. Selection, use and care of protective equipment and

clothing. First aid, including self-treatment. Dealing with emergencies such as fires, leaks and

spills. Good housekeeping practices. Knowledge of all the hazards of the materials you

work with e.g.. fire, explosion, health, chemical reactivity.

Safety systems including gas specific connectors, relief valves and burst discs.

Housekeeping

All doors must be labelled. If Nitrogen, Nitrous Oxide, or Carbon Dioxide is in the room, label per pages 25 and 26. If Oxygen or Air only, label as per pages 27 and 28.

Ensure that proper housekeeping practices in the workplace are followed at all times.

Safe Work Practices

Do not allow smoking or open flames in any area where liquid oxygen is stored, handled or used.

Do not contaminate cryogenic liquids or their containers.

Never allow combustible organic materials near liquid oxygen.

Prevent the mixing of flammable and oxidizing cryogens.

Never allow any absorbent materials to be exposed to flammable or oxidizing cryogens.

When venting storage containers, proper consideration must be given to all the properties of the gas being vented.

Ensure Ventilation is in operation at all times.

Storing and transporting cryogenic liquids

Inspect all incoming containers before storing to ensure they are not damaged and are properly labelled.

Do not accept delivery of defective containers. Always use the correct name for all materials, e.g.

never call liquid oxygen liquid air. Do not store containers where they may come into

contact with moisture. Moving parts, such as valves or pressure relief devices, can malfunction due to external ice formation.

Allow only authorized people into storage areas. Ensure that ignition sources and combustible material

are kept far away from liquefied oxygen, and other flammable material storage and handling areas.

Do not store liquid oxygen containers on wood, asphalt or oil soaked gravel. When saturated with liquid oxygen these materials can explode after an impact as slight as a footstep.

Use concrete or clean gravel under storage areas. Ensure that vessels are insulated from any sources of

heat. Handle cylinders carefully, and avoid dropping,

rolling or tipping them on their sides. Do not move a container by rolling it on its lower

rim. Always use a hand truck, cart, or other proper

handling device when transporting cryogenic liquid containers. Use a strap to secure the container to the handcart.

Keep the cryogenic liquid containers upright at all times except for the minor tilting on the cart during transport.

For the most current and up-to-date information on cryogenics refer to the label on the container and the Material Safety Data Sheet (MSDS), available from distributors/manufacturers.


Working with cryogenic containers

When containers are not labelled or little information is known of the contents, they should be treated with extreme caution. Never assume an unmarked container contains any specific gas.

For hazardous operations a permit to work system should be in place.

Use only the stopper or plug supplied with the container when sealing it.

Prevent all organic substances including oils and greases from contacting liquid oxygen.

Never wear watches, rings, bracelets or other jewellery that could freeze to your skin.

Thoroughly clean any equipment or container used with liquid oxygen to the degree required for use with oxidizing materials.

Ensure warning signs and emergency instructions are posted wherever cryogenic containers are used or stored.

Always follow the manufacturers procedures for operating and maintaining equipment used with cryogens.

Avoid forcing connections, never use cheater hoses, adaptors from one gas specific fitting to another, or hoses and fittings without permanent gas specific ends.

Never tamper with containers in any way. When doing maintenance work on oxygen handling

systems, cleanliness is essential. Grease or oil must not be allowed to contaminate any parts.

Cryogenic liquids should NEVER be transferred from one container to another or transfilled except in appropriately equipped facilities by trained operators.

Contact with cryogens

If bodily contact occurs with cryogenic liquids, their vapours and any cooled surfaces, flush the area with large quantities of warm (not hot) water. If the skin is blistered or the eyes have been exposed, obtain medical attention immediately.

Emergency eyewash stations and, if possible, safety showers should be provided when working with cryogens.

Remove clothing that is splashed with liquid oxygen immediately and air it out for at least one hour.

Personal protective equipment (PPE)

The following personal protective equipment should always be used when working with cryogens.

Loose fitting insulated gloves when handling anything that may have been in contact with a cryogen, e.g.. Insulated welding gloves.

Safety glasses. A non-porous, knee length laboratory coat, without

pockets or cuffs which could catch the liquid. Boots with tops high enough to be covered by pants

without cuffs.

Safe Work Practices


Alarms and Alarm Response

Annex CAlarms and Alarm Response

Liquid manifolds require specific alarms, and because of the nature of the containers require more actions be taken when an alarm sounds. The alarms are valuable indicators, but they are only indicators, and determining what must be done in response requires a person knowledgeable in the operation and peculiarities of the manifold.

The three required alarms are: Changeover, which indicates the primary header is

empty and the secondary header is in service. Reserve In Use, which indicates the Primary and

Secondary headers are empty and that the Reserve header is now supplying the system.

Reserve Low, which indicates the Reserve Header is below one average days supply.

These alarms must appear at both master alarm panels (or at the one master alarm in a level 2 facility). They must also have Local Signal analogues at the manifold itself. Local signals are not alarms in that they are not audible, and may be any kind of device which enables the operator to determine the state of the system when standing at the manifold. Marked gauges, flippers, lights, flags, etc. all may qualify as local signals.

Two system alarms are also required at both masters: System Pressure High, indicating system pressure is 20%

or more above normal. System Pressure Low, indicating system pressure is 20%

or more below normal.

In normal operation the alarms will cascade as follows:Changeover, followed by Reserve In Use, followed by Reserve Low, followed by System Pressure Low when the manifold is entirely exhausted.

To lose supply therefore, the facility must ignore three alarms. This usually will be adequate coverage, but only if with each alarm action is taken.

With a Changeover alarm, the operator should: With a semi automatic manifold, confirm the switchover

by whatever method is provided. (This step is not needed on a fully automatic manifold.)

Examine the containers on the Secondary bank and determine that both are empty. If so, replace with full containers. If not, this indicates a problem with the operation of the containers or the manifold (a common finding is a pressure builder not opened).

Examine the container(s) on the Primary Bank. A decision will be required based on how full these containers are. They may be left in service or replaced.

If nearly empty, it is often better to replace them to save labor, but this means not fully using the container contents. The decision to be made will vary between facilities and on the usage at the time.

Examine the contents of the reserve header. If the contents are low, these must be replaced as well.

With a Reserve in Use Alarm, the operator should: Examine the containers on the Primary and Secondary

banks and determine that all are empty. If so, replace with full containers. If not, this indicates a problem with the operation of the containers or the manifold (a common finding is a pressure builder not opened).

Examine the contents of the reserve header. If the contents are low, these must be replaced as well.

With a Reserve Low Alarm, the operator should: Examine the containers on the Primary and Secondary

banks and determine that there is gas in each. If not, replace with full containers. It is not uncommon to have a Reserve Low alarm occur despite the Primary and Secondary headers being in service. Reserve headers can weep either into the system because no regulator is entirely leak tight or through leaks at the cylinder connections. If this occurs, the Low Contents alarm will eventually sound.

Examine the contents of the reserve header. If the contents are low, these must be replaced. Note that with a new system it is possible to have the header sized for a 24 hour supply, which means the alarm must sound if the header loses any gas at all. This is a sizing problem which can only be solved by enlarging the header and adjusting the switch.

Remember that the Reserve will still have considerable gas in it when the alarm rings. Inexperienced operators can be fooled when they look at the gauge and see the cylinders are still mostly full. They may decide to not change the cylinders and ignore the alarm. There is no better way to guarantee the system will run empty sooner or later.

It is entirely possible that all three of the operating alarms can ring virtually simultaneously. This is most likely when the facility operates at low usage, and is inevitable if they operate below the NER. Such an event indicates that all three headers are essentially out of gas, and requires the most rapid response to avoid system failure. All containers and cylinders will normally need to be replaced. If this happens often, the facility has an oversized system, and they should consider making changes which will reduce the NER and cause the manifold to return to operating in a proper cascade. Continued operation in this mode is very high risk.

If the manifold is operating and has full supplies, but the Low Pressure Alarm sounds, (with or without other alarms)


this is a possible indicator of overdraw. Typically, the alarm will be intermittent and in some cases can even be traced to the operation of a specific piece of equipment, like a nitrogen tool in the O.R. When this occurs, it is necessary first to determine that overdraw at the manifold is indeed the cause. This will best be done simply by observation. Symptoms to look for include: Liquid containers running at low pressures. Every

container has a normal pressure range for which the pressure builder is set, and the container should be operating close to that range. There are two common causes for low container pressures (other than that the container is empty): a closed pressure builder and a buildup of ice. If the pressure is low, check first to ensure the pressure builder is open. If heavy ice has accumulated, you may need to melt it off to restore the containers function.

The wrong type of containers. This is particularly a problem with high pressure systems like nitrogen. Such systems need a high pressure container in order to perform correctly, and if a low pressure container is used the output of the manifold may be inadequate.

Seeking at the manifold. If the manifold is swinging back and forth between Primary and Secondary headers (which may also be causing the Changeover alarm to sound), this may be occurring because the manifold is looking to satisfy the demand by drawing off both headers.

Alarms and Alarm Response


Cyl

inde

rs In

Sto

rage Cylinders O

n Secondary

Cylinders On Reserve

Liquid Containers

Secure Door with lock

One Hour (or greater)Fire resistive construction

Cable or chain restraints

ExtractionBlower

(intake at floor)

Air inlet(at ceiling)

Figure D-1An Example of a Liquid Manifold Installation

Minimumof 155

(393 cm)

Minimum of 90 (239 cm)

Annex DA Manifold Room Layout(also see Annex H for outdoor locations)

The following is a typical layout for a manifold room. This is by no means the only way to lay out a manifold nor necessarily the best. Every situation must be evaluated on its own. However, this is included to help define some of the important criteria for an effective manifold layout.

Figure D-1 illustrates a Liquid by Gas manifold with the necessary gas cylinder reserve.

The diagram illustrates required features including: All elements of the manifold system are in the same enclosure. The enclosure (in this case inside the building) is of 1 hour fire resistive construction.All cylinders and containers are restrained. A single cable is illustrated, but individual restraints for each cylinder and container are required under the 2002 standard (a requirement which appears only in that one edition). Note that the loose cylinders (full or empty) are also restrained. The room is provided with a mechanical ventilation system as required ny NFPA 99. In addition, the ventilation system has an intake for make up air. The extraction is at floor level, the make up air

at ceiling level. The reserve is placed at an angle to the main manifold. This is entirely optional, but can save considerable space. The Secondary and Reserve are the same number of cylinders. This is not mandatory, but is common

Manifold Layout


Manifold Layout

practice. Sufficient room has been allowed for manipulation of the liquid containers. However, no provision has been made for cylinder or container handling equipment (handtrucks, etc.) which are commonly stored in these rooms. No provision has been made for storage of liquid containers. These generally should be stored outside, where any gas they will discharge is not confined. If this enclosure were open and out of doors, there would need to be room provided for these standby and empty containers.


Gas Manifold Dimensions

Dimensions

Liquid manifolds present unique challenges as to space and arrangement. The following sections give basic dimensional information and some examples of Liquid manifold layouts for the guidance of the designer.

45 (111.8 cm)

61155 cm

84213 cm

96244 cm

WALL

Recommended minimum access clearance

20 (50.8 cm) Recommended cylinder space11 (27.9 cm) manifold enclosure front

Cylinder Header

System Connection (Typ.)

Ceiling (Typ.)

Note1

Note 1 : Overall Manifold Minimum Space Allocation(Outermost cylinder to outermost cylinder, staggered cylinders)

# Cylinders per header (total cylinders is 2x this number) 2 3 4 5 6 7 8 9 10 11 12 13 14 21 36 47 57 67 77 87 97 107 117 127 137 14753 cm 91 cm 119 cm 145 cm 170 cm 196 cm 221 cm 246 cm 272 cm 297 cm 323 cm 348 cm 373 cm Minimum permitted number of cylinders is two x two (ref. NFPA 99 5.1.3.4.10.4 (2))Other cylinder header configurations are possible. Consult your BeaconMeds representative for exceptional situations.

TM

Lifeline Gas x Gas ManifoldMinimum Clearance Dimensions

11/2004

MWA

Gas Manifolds


Liquid x Liquid Manifolds

TM

Lifeline Liquid x Liquid ManifoldMinimum Clearance Dimensions

11/2004

MWA

45 (111.8 cm)

56 (143 cm)

61155 cm

84213 cm

96244 cm

WALL



Ceiling (Typ.)

26 (66 cm)Recommended

container space(will vary with

containers used) Recommended minimum cylinder access clearance

Recommended minimumcontainer access clearance

26"(66 cm)1

52(132 cm)1

1 Recommended minimum design dimension is shown. Actual containers vary in diameter.2 Dimension is variable and Reserve may be located wherever convenient so long as it does not interfere with other cylinders or containers.

Note2 Note3

Note 3 : Reserve Cylinder Header Minimum Space Allocation(Point of connection to outermost cylinder, staggered cylinders)

# Cylinders 3 4 5 6 7 8 9 10 11 12 13 14 30 35 40 45 50 55 60 65 70 75 80 8576 cm 89 cm 101 cm 114 cm 127 cm 139 cm 152 cm 164 cm 178 cm 190 cm 203 cm 216 cm Minimum permitted number of cylinders is three (ref. NFPA 99 5.1.3.4.10.4 (2))Other cylinder header configurations are possible. Consult your BeaconMeds representative for exceptional situations.

Liquid Manifold Dimensions


45 (111.8 cm)

61155 cm

84213 cm

96244 cm

WALLWALL


Reserve CylinderHeader

Secondary CylinderHeader


Ceiling (Typ.)

26 (66 cm) Recommendedcontainer space(will vary with containers used) Recommended minimum cylinder access clearance

56 (143 cm)

Recommended minimumcontainer access clearance

26"(66 cm)1

52(132 cm)1

Note4

Note2

Note3

1 Recommended minimum design dimension is shown. Actual containers vary in diameter.2 Dimension is variable and Reserve may be located wherever convenient so long as it does not interfere with other cylinders or containers.

Note 3 : Manifold Cylinder Minimum Space Allocation(Cabinet centerline to outermost cylinder, staggered cylinders)

# Cylinders 2 3 4 5 6 7 8 9 10 11 12 13 14 10.5 18 23.5 28.5 33.5 38.5 43.5 48.5 53.5 58.5 63.5 68.5 73.527 cm 46 cm 60 cm 72 cm 85 cm 98 cm 110 cm 123 cm 136 cm 149 cm 161 cm 174 cm 187 cmMinimum permitted number of cylinders is two (ref. NFPA 99 5.1.3.4.10.4 (1))Other cylinder header configurations are possible. Consult your BeaconMeds representative for exceptional situations.

Note 4 : Reserve Cylinder Header Minimum Space Allocation(Connection point to outermost cylinder, staggered cylinders)

# Cylinders 3 4 5 6 7 8 9 10 11 12 13 14 30 35 40 45 50 55 60 65 70 75 80 8576 cm 89 cm 101 cm 114 cm 127 cm 139 cm 152 cm 164 cm 178 cm 190 cm 203 cm 216 cm Minimum permitted number of cylinders is three (ref. NFPA 99 5.1.3.4.10.4 (2))Other cylinder header configurations are possible. Consult your BeaconMeds representative for exceptional situa-tions.

TM

Lifeline Liquid x Gas ManifoldMinimum Clearance Dimensions

11/2004

MWA

Liquid x Gas Manifolds

Liquid x Gas Manifold Dimensions


Annex FSignage

Page 25: English, for manifold rooms containing only oxygen or air.Page 26: Spanish, for manifold rooms containing only oxygen or air.Page 27: English, for manifold rooms containing any gas other than oxygen or air.Page 28: Spanish, for manifold rooms containing any gas other than oxygen or air.

Signage


Signage


Bulk and MiniBulk Implementations

Annex GUsing Bulk and MiniBulk Sources with the Lifeline Manifold

The Lifeline manifold can act as controller for a bulk or minibulk installation and such an installation may be the very best way to serve a medium sized facility. There are a number of important considerations which must be accounted for in order to have a satisfactory system. They include: Siting. The location of a system which contains more

than 20,000 ft3 is subject to additional rules above those applicable to manifolds. BeaconMeds recommends these rules should be considered as applying to any installation involving stationary liquid containers.

Please refer to the drawing in Appendix H for siting requirements.

BeaconMeds recommends that stationary container installations always be out of doors. Although it is possible under NFPA 99 to place some minibulk systems indoors (eg. those with contents under 20,000 ft3), the practice is fraught with problems which are better avoided. Although the NFPA 99 has defined a 20,000 ft3 limit for systems placed indoors, there is no magic to this number. The real concern begins when liquid containers come indoors and simply worsens as the containers get larger. While there are compelling reasons to bring portable containers indoors in some cases, those arguments grow less and less acceptable as the volume increases and are largely invalid once the container is made stationary. However, it is entirely possible to place the stationary container outdoors and the manifold, secondary and reserve indoors (see Figure G-1).

Configuration of the system. Please see Figure G-1 for a general configuration diagram.

Pressure output. A bulk or minibulk can output at higher pressures than is typical of portable containers and the output pressure is important to overall function.

As with any manifold, the Lifeline manifold will improve in flow capacity with higher inlet pressures. Therefore, with a stationary container, the pressures should be as high as is consistent with the container capabilities, and low pressure containers should not be used.

Sample Manifold throughputs at varying input pressures

Inlet pressurepsi/kPa

Flow ft3h / liters per hr.

150 / 1,035 2,220 / 62k

300 / 2,070 3,660 / 103k

450 / 3,105 6,420 / 181k

Vaporization. BeaconMeds recommends external vaporizers always be used with these installations.


Reserve C

ylinderH

eaderSecondary C

ylinderH

eader

Bulk or M

iniBulk System

(including all necessary controls, ie. pressure builder, regulators if required)

Figure G-1

Implem

enting a Lifeline Manifold as a C

ontroller for a Stationary Container

Duplex External V

aporizer Set w

ith controls

Locating the Stationary container outdoors is recom

mended but m

ay not be required. Fill connection and term

ination of all relief valve vents outdoors is absolutely m

andatory.

Locating the manifold, secondary header and reserve header indoors is not

required but may be desirable in som

e climates. M

anifolds and cylinders located outdoors m

ust be protected from direct sun, rain etc. and cylinders

must be m

aintained at >32F and

cryogenic manifolds

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